Calories in Bread
A typical slice of bread (28g) contains 75–85 kcal. Whole-wheat is similar in calories to white but has 2–3g more fiber per slice. Sourdough has a lower glycemic index.
Nutrition by portion size
| Portion | kcal | Carbs (g) | Protein (g) | Fat (g) | Fiber (g) |
|---|---|---|---|---|---|
| 1 slice white bread (28g) | 75 | 14 | 2.5 | 1 | 0.7 |
| 1 slice whole-wheat (28g) | 81 | 14 | 4 | 1.1 | 2 |
| 1 slice sourdough (35g) | 95 | 18 | 3.5 | 0.6 | 1.2 |
| 100g white bread | 265 | 49 | 9 | 3.2 | 2.7 |
| 100g whole-wheat bread | 247 | 41 | 13 | 4.2 | 7 |
| 1 bagel (~95g) | 245 | 48 | 10 | 1.5 | 2 |
Per 100g — variant comparison
| Variant | kcal | Carbs (g) | Protein (g) | Fat (g) | Fiber (g) |
|---|---|---|---|---|---|
| White bread | 265 | 49 | 9 | 3.2 | 2.7 |
| Whole-wheat bread | 247 | 41 | 13 | 4.2 | 7 |
| Sourdough | 271 | 51 | 9.7 | 1.8 | 3.5 |
| Rye bread | 259 | 49 | 8.5 | 3.3 | 5.8 |
| Ezekiel/sprouted | 260 | 51 | 13 | 1.5 | 5 |
About these numbers
Bread is one of the most consumed foods globally and one of the most varied in nutritional profile. White bread has a high glycemic index (73), low fiber, and is essentially refined starch. Whole-wheat bread retains more of the bran (3x fiber) and has a slightly lower GI (~67). Sourdough's long fermentation process partially breaks down carbohydrates, producing GI as low as 50–55 — substantially better for glucose control than typical white bread.
For practical eating: a typical slice is about 28g (75–85 kcal). The mental math "2 slices of bread = 160 kcal" is a useful baseline. Bagels are calorie-dense outliers — a single bagel is 250+ kcal (equivalent to 3 slices of bread) but feels like one serving. For weight loss, bagels need conscious portion awareness.
Use the calculators
- Calorie Deficit Calculator — find how this portion fits your daily target
- Glycemic Load Calculator — compute exact GL for any serving size
- Macro Calculator — set protein, carb, fat splits for cut/maintain/bulk
- Net Carbs Calculator — useful for keto and T1D insulin dosing
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Frequently asked questions
- How many calories are in a slice of bread?
- A typical slice of bread (28g, the USDA standard slice weight) contains 75–85 kcal. White bread is at the lower end (~75 kcal); whole-wheat is slightly higher (~81 kcal). A thick "Texas toast" slice can be 50% larger and 120 kcal. Sourdough slices are often larger (~35g) at 90–100 kcal. Bagels are dramatic outliers — a single bagel can be 245–360 kcal.
- Is whole-wheat bread better than white bread?
- Yes, for most metabolic markers. Whole-wheat has 3x the fiber (7g vs 2.7g per 100g), more vitamins and minerals, slightly lower GI (~67 vs 73), and produces a more sustained satiety response. The 2018 Reynolds et al. Lancet meta-analysis on fiber and chronic disease included whole-grain bread as a primary source contributing to 15–30% reductions in CVD, T2D, and all-cause mortality. White bread is fine in moderation but isn't the better default for any health-related goal.
- Is sourdough healthier than regular bread?
- For glucose response, meaningfully yes. The natural fermentation process partially breaks down starches and creates lactic acid, both of which slow glucose absorption. Sourdough's GI can be as low as 50–55 (well below regular bread's ~73). The 2009 Maioli et al. study showed sourdough reduced post-meal glucose response by 22% vs equivalent yeast-leavened bread. For people with diabetes, prediabetes, or anyone CGM-tracking, sourdough is a meaningful upgrade from regular bread. Caloric content is similar.
- Can I eat bread on a diet?
- Yes. A slice of bread is 75–85 kcal — fits easily in any reasonable calorie target. The trap is portion (eating 4–5 slices a day adds 300–400 kcal without much satiety contribution) and toppings (a single Tbsp of butter or olive oil adds 100+ kcal). For weight loss, 1–2 slices per day of a whole-grain or sourdough variety, treated as a calorie-budgeted item rather than a free addition, works for most adults.
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